Arylpyrrole carbonitrile compounds and derivatives thereof are highly effective insecticidal, acaricidal and nematocidal agents. In particular 2-aryl-5-trifluoromethylpyrrole-3-carbonitrile compounds and their derivatives have been found to have a broad spectrum of activity at very low rates of application with effectiveness against resistant species. U.S. Pat. No 5,030,735 describes methods to prepare said pyrrole compounds on a manufacturing scale and includes the 1,3-dipolar cycloaddition of the appropriate 3-oxazolin-5-one with 2-chloroacrylonitrile. Heretofore the 3-oxazolin-5-one key intermediate has been prepared through the appropriate phenylglycine compound in a 4 step synthetic route starting from the preceding aminonitrile.
It is an object of this invention to provide a facile and efficient synthesis of 2-perfluoroalkyl-3-oxazolin-5-one in 2 steps from the aminonitrile precursor.
It is a further object of this invention to provide a convenient source of a key intermediate in the manufacture of insecticidal, acaricidal and nematocidal arylpyrrole compounds.